In connection with the background of the present invention, a brief review of the history of anchors is appropriate. First, the earliest forms of anchors involved a simple weight, such as a heavy rock tied with a rope, or the like. Subsequently, anchors were designed with structures for digging into the bottom of a body of water. These included mushroom type anchors and anchors with flukes, or pointed members which would dig into the ground. Further, in order to orient the flukes so that they would dig into the ground and not merely lie flat on the bottom of the body of water, cross pieces, known as "stocks" were attached to the bottom of the anchor crosswise to the flukes. Accordingly, the anchor normally included the flukes, an extended shank to which the ship or vessel's cable was attached and a cross piece or stock to maintain the fluke or flukes in the proper orientation to dig into the bottom of the body of water. Normally, it is desirable to use a length of cable which is equal to 6 or more times the depth of the water where the vessel is being anchored. When the shank of the anchor is pulled substantially horizontally, the flukes will then dig in to the bottom of the body of water and hold the vessel against movement.
One of the problems which arose in the use of these relatively complicated anchor structures was the matter of storing the anchors so that they could be deployed quickly and easily. In view of the complicated structure including the shank, the pointed flukes, and the cross piece or stocks which were employed, the resultant structure was awkward, cumbersome, and difficult to store. One solution which was developed was the so-called "stockless" anchor which included two flukes which were pivoted together, relative to the shank of the anchor so that when the anchor was initially lowered, the entire structure could lie flat on the bottom of the ocean, with the pair of flukes pointing back along the shank of the anchor from the pivot region at the far end or "crown" of the anchor. The pair of flukes was capable of pivoting up to about 30 or 40 degrees in either direction from the shank, and when tension was applied to the shank of the anchor, the flukes would dig in and hold the anchor against movement. On the other hand, when the cable to the vessel was shortened, the flukes would be tilted upward and out of the earth or sand at the bottom of the ocean so that the anchor could be freely raised. Further, the relatively flat structure of the "stockless" anchor permitted easier storage, for example, against the outer surface of the hull of a large ship, when the shank of the anchor was pulled up into the "Hawsepipe" through which the chain was drawn into the vessel by a winch or the like.
Another popular anchor which has a relatively low weight to holding power ratio is the plow type anchor, also known as the C.Q.R. anchor. This includes a single plow-shaped fluke or holding member which is pivoted relative to the shank so that, when the shank is pulled horizontally, the plow digs into the bottom of the body of water.
In the last decade, a new form of anchor, known as the Bruce anchor, has started to enjoy considerable popularity. It has a very low weight to holding power ratio, and also has the advantage over the stockless and the C.Q.R. or plow anchors that it has no hinge or pivot structure which can become fouled or entangled with the anchor cable. The Bruce anchor has an L-shaped shank with the shorter leg of the L at the crown or most remote portion of the anchor. Extending back generally parallel to the longer portion of the shank is a large shovel-shaped fluke, and two smaller curved flukes curve outward and up toward the end of the main shank on either side of the large area central fluke. The broad area at the base of the flukes has a passing correspondence to the palm of a persons' hand, and is therefore occasionally referred to as the palm or the fluke area of the anchor. As noted above, the Bruce anchor is a very efficient anchor for its weight; unfortunately, however, with its rigid and extended structure, it is relatively awkward to store.
Accordingly, a principal object of the present invention is to provide an arrangement for not only raising and lowering anchors of the Bruce type, but also for securing them when the vessel is under way.